\documentclass{article}
\usepackage{amssymb,amsmath,amscd,concmath}
\pagestyle{empty}
\begin{document}
\begin{equation*}
\mbox{flag}_{\mbox{Poland}} = \left ( \begin{matrix} \mbox{ white } \\ \mbox{ red } \\ \end{matrix} \rigth )
\end{equation*}
\end{document}
